Question Getting intermittent high packet loss or lag spikes a few hours after plugging wireless access point ?

[willis9829]

Issue:
My AP is on IP address 192.168.1.4 and when this issue happens any device wireless or hardwired shows a lot of packet loss during ping test.


I have the following topology:

AT&T BGW320-505 gateway router ( in IP passthrough mode) --> EdgeRouter X 2.0.9-hotfix 4 --> Ubiquity EdgeSwitch 8-150W v1.9.3-lite --> EngeniousTech EWS357AP v3 access point v3.9.3_c1.9.51

More info:

It seems to have started once I hung AP on the ceiling and ran CAT 6 10ft cable to port to which I connect my switch but I tested the cable using cable tester and all 8 lines light up green and probably if cable was bad I would see the issue right away after plugging.

Coincidently it started after I had ATT Fiber installed to replace cable internet connection but I don't see how it could only affect AP but no other networking devices in the chain.

I broadcast from it 2 SSIDS tagged with different vlans to separate my iOT devices from other devices. Both 2.4Ghz and 5Ghz are in green operation mode letting AP to auto configure transmit power.

Troubleshooting
I noticed when looking at cpu, memory usage on AP, I often get between 5-30% with peak as high as 50% even though memory usage and when network traffic is low. I only have 10 devices connected in my home network.

I saw a few interface error counters on my switch port connecting my AP.

 

[bill001g]

How are you running your ping test. Are you using some tool the internet or are you manually ping your router IP.

When you say you get packet loss hardwired you mean you plug a pc into your edgerouter and it also gets packet loss?

If you get packet loss cabled to the router then it eliminates the wifi and the AP as the cause.

I know the ATT router has a speedtest feature does it also have a ping test that you could run. That would eliminate all the equipment in your house.

 

[willis9829]

How are you running your ping test. Are you using some tool the internet or are you manually ping your router IP.

When you say you get packet loss hardwired you mean you plug a pc into your edgerouter and it also gets packet loss?

If you get packet loss cabled to the router then it eliminates the wifi and the AP as the cause.

I know the ATT router has a speedtest feature does it also have a ping test that you could run. That would eliminate all the equipment in your house.

No it's not router or any flavor of consumer routers with built in switch and AP. It's a dedicated AP Engenious-Tech EWS357AP which has its own IP address. I am saying whether I ping it from a laptop over its 5Ghz network to itself or from switch that is hardwired to this AP I get intermittent high packet loss or sometimes spike lags like above 300 ms. Once I power it off and power it on again it typically resolves the issue until few hours later. Also when this issue happens and ping from a wired device to a router or switch instead of the AP I see no connection issues.

I have Monoprice Cat6 10ft bootzero cable running alongside wall from the AP mounted on the ceiling to box mounted near my network stock with keystone jack inliner and from that jack to PoE switch using a flat Cat6 5ft cable.

I decided to unmount it and connected it directly using cat6 flat cable and now it seems to operate more stable which seems to point to the long run stranded cat6 cable as culprit, although the cable tester did not show any issue on any stand of 8 wires inside.

 

[bill001g]

You should not use flat cable especially when you are running PoE over it. Almost every flat cable in existence uses wire that is not awg 22-24. That immediately disqualifies it as being a certified ethernet cable. It might work in some subset of cases but there is no way to tell.

The cable testers us normal people can afford will not be able to detect things like wires the wrong size or lack of proper twist in the cable or between cables. They purely test if I put a battery on one end does it light a led. It does not in any way determine if the cable will actually pass data.
It is though good enough for home use when you know the cable you are using is quality cable to begin with.

Instead of ping the AP IP i would take a device that is attached via the AP and ping the router IP. The IP address on the AP is only really used for management, the end user traffic does not pass through that part of the AP on a regular basis. Many AP, and even commercial routers, will drop a ping packet to the devices IP if it is using its cpu to do more important things...like passing user data. Now if you also get loss when you were to ping your router or even another pc connected to the router via ethernet then you start to suspect some issue with the connectivity of the AP.

Mostly be sure you have a actual issue rather than some testing abnormality.

 

[willis9829]

You should not use flat cable especially when you are running PoE over it. Almost every flat cable in existence uses wire that is not awg 22-24. That immediately disqualifies it as being a certified ethernet cable. It might work in some subset of cases but there is no way to tell.

The cable testers us normal people can afford will not be able to detect things like wires the wrong size or lack of proper twist in the cable or between cables. They purely test if I put a battery on one end does it light a led. It does not in any way determine if the cable will actually pass data.
It is though good enough for home use when you know the cable you are using is quality cable to begin with.

Instead of ping the AP IP i would take a device that is attached via the AP and ping the router IP. The IP address on the AP is only really used for management, the end user traffic does not pass through that part of the AP on a regular basis. Many AP, and even commercial routers, will drop a ping packet to the devices IP if it is using its cpu to do more important things...like passing user data. Now if you also get loss when you were to ping your router or even another pc connected to the router via ethernet then you start to suspect some issue with the connectivity of the AP.

Mostly be sure you have a actual issue rather than some testing abnormality.

Thanks

I notice when this happens before I test, loading websites stall or zoom call drops, even Nest Guard IoT wifi device looses connection and shows "offline". I will get a thicker cable toto replace the flat one and see if this fixes issue. Perhaps on its own works fine but when coupled with another it has issues.